1. Field of the Invention
The invention relates to an X-ray imaging method in which a series of two-dimensional X-ray images is formed and digitally stored, an object to be examined which is situated in an examination zone being projected onto an X-ray image pick-up device from different perspectives and voxel image values being reconstructed from the image values of the X-ray images for voxels present in the examination zone, and also relates to the device for carrying out the method.
2. Description of Related Art
A method and a device of the kind set forth are known from EP-A-492 896. Therein, X-ray images are formed from perspectives which differ 180.degree. (or more). Nevertheless, the data thus acquired is not complete because the X-ray beam does not cover the edges of the object to be examined so that some X-ray images contain structures of the object to be examined which are absent in other X-ray images.
In order to reconstruct the voxel image values (herein voxels are to be understood to mean volume elements of the examination zone) use is made of an iterative method in which, in addition to the data of the X-ray images, a priori information concerning the outer contour of the object to be examined is taken up in the reconstruction. This method requires a large amount of calculation work on the one hand and, on the other hand, is not suitable for the imaging of the vascular system because it is a prerequisite that the vascular system is filled with a contrast medium in all X-ray images. This condition can hardly be satisfied in practice.